Heather's take on Boo's Ridiculous(ly low calorie) Brownie with a shiny, crinkled crust created using erythritol as a sweetener in place of sugar. Bird's eye shot on parchment paper on a wooden stool as backdrop :)
brownies chocolate desserts low cal low cal: vegan recipes

Boo’s Ridiculous Brownies (29 calories & anabolic)

Why enjoy a piece of your regular brownie when you can have the whole tray to yourself? Packed with protein and boasting under 29 calories per piece (we’re looking at 456 calories for the entire 8×8 pan!), Boo’s Ridiculous Brownies have truly lived up to their name. They’re gluten-free, nut-free, egg-free, and can be made vegan and low carb too – no weird ingredients!

{Gluten-Free, Sugar-Free, Oil-Free, Nut-Free, Dairy-Free, Eggless, with Keto and Vegan-friendly options!}

It’s been a hot minute since I’ve posted, but fear not, for my exams are finally over (still feels so surreal typing this )! Fingers crossed that with more time on my hands, I’ll be able to upload more low-calorie and macro-friendly recipes this summer ☀️

While I haven’t had the time to develop recipes during exam season, I’ve stumbled across countless healthy recipes on Instagram, Youtube, and Reddit that looked incredibly promising, which of course, I had to review and share with you guys!

We’re starting off with Instagram creator @lowcalrecipes98‘s famous low-calorie and anabolic Ridiculous Brownies. If you’ve been hanging out in the low-calorie corner of the internet for the past couple of months, Boo’s Ridiculous Brownies recipe should ring a bell. Chances are, you’ve probably tried one of the many variations she’s tested – they’re all over the internet, and for good reason!

I’ve actually been eyeing Boo’s Ridiculous Brownies recipe for months, but have never gotten round to making them. I was always short of an ingredient (and time to acquire le goods 🥲)… until today. And holy crap they did not disappoint!

I mean, just look at that crust! Drool worthy.

Low calorie brownies with a shiny, crinkled top created using erythritol as a sweetener in place of sugar, baked in a glass dish pan.
Photo courtesy of @ronny.d.fitness on Instagram

Donut Brownies. Mindblown.

Boo's Ridiculous Brownies turned-donuts; frosted with chocolate spread and topped with multicolored sprinkles. Low calorie and high protein.
Photo courtesy of u/tartineauchocolat on Reddit (link here)

And a photo from the creator herself:

A 2 inch square piece of Boo's Ridiculous(ly low calorie) Brownie with a shiny, crinkled crust created using erythritol as a sweetener in place of sugar.
Photo courtesy of @lowcalrecipes98 on Instagram

Still not convinced?

Here’s why you need to MUST try Boo’s Ridiculous Brownies…

#1 Nutrient Content
  • For the whole tray, we’re looking at 457 calories. This means only 28.5 calories per 2″x2″ piece!
  • Macros are pretty dope too – 43.5g of protein for the entire batch, thanks to the addition of protein powder!
  • For reference, a quick Google search indicates that the average 2″ square brownie contains 112 calories and 1.5g of protein. I’m just sayin’😉
#2 Affordable & Accessible Ingredients
  • That’s right! No strange/expensive ingredients of the likes of oat fibre, psyllium husk powder, or xanthan gum. And to my surprise, no egg whites either!
  • Boo’s Ridiculous Brownies recipe only calls for pantry staples, and all ingredients may be swapped out to meet your dietary requirements. Scroll down for recommended substitutes! 🙂
#3 Allergen-friendly & Inclusive of Dietary Restrictions
  • These low-calorie brownies are gluten-free, nut-free, vegan (egg-free and dairy-free), and can be made paleo/keto. Scroll down for recommended substitutes! 🙂
  • Boo actually has a whole post on substitutes she recommends, and you can find heaps more variations shared by commenters underneath her posts. For convenience’s sake, I’ve included the most popular ones below (you’re welcome hehe). Make sure to check out Boo’s Instagram @lowcalrecipes98 for more!
#4 One Bowl and Insanely Easy
  • I also love these low-calorie brownies because they literally take ten seconds to make. Okay, more like 30 minutes but since you won’t need a mixer, double boiler, or measuring cups, you’ll spend less time cleaning up 😉
  • All you’ll need is a 330ml can of zero-calorie soda or carbonated drink, and a food scale to weigh out the 6 other dry ingredients. Simply mix everything together, pop it in the oven/air fryer/stove, and voila, you’ve got yourself a tray of Ridiculous Brownies! It’s that simple.

Appearance and flavour wise, these healthy brownies are on par with your regular ol’ brownie too! Clearly, Boo really wasn’t kidding when she named them Ridiculous Brownies 🤪

Texture and crust are *chef’s kiss*!

A square piece of Boo's Ridiculous(ly low calorie) Brownie with a shiny, crinkled crust created using erythritol as a sweetener in place of sugar. Screenshot taken from a follower's Instagram story reposted by Boo @lowcalrecipes98.
Photo courtesy of @munchingonlunch on Instagram

Okay, before I keep babbling on, let’s talk ingredients. The base recipe for Boo’s Ridiculous Brownies only calls for 7 common pantry ingredients, but there are tons of substitutes that work great too – the recipe is incredibly versatile and forgiving.

Ingredients and Recommended Substitutes

#1 All Purpose “AP” Flour (45g)
  • Wheat Flour (white, whole wheat, cake flour, bread flour)
  • Gluten-Free: Oat Flour (I used this!), Rice Flour in equal amounts
  • Low Carb: Almond Flour (42g), an Instagram user used Oat Fibre (30g)
#2 Chocolate Whey Protein Powder (36g)
  • Whey/Casein blend: I used Select Protein Chocolate Cupcake by PEScience (click for $10 off your first order!), which Linda Sun loves too!
  • Vegan: Soy protein, Pea protein (IMO stick to flavoured pea protein since it has an earthy taste)
fluffy and thick pancakes that are low calorie and high protein pancakes made using pea protein isolate, topped with PB2 (a pinterest graphic)

psssst… a great pea protein pancake recipe for my dairy-free and low-carb bakers!

#3 Erythritol (135g) – provides volume and yields a shiny crust!
  • Regular Sugar, Monkfruit sweetener, Xylitol in equal amounts
  • Swerve, but Boo says to use less
  • Stevia won’t work well (based on comments on Instagram)
  • Boo’s original Ridiculous Brownies recipe calls for 135g of erythritol, which I reduced to 100g. If you don’t have much of a sweet tooth or use a very sweet protein powder, feel free to reduce this by a further 20-30g!
#4 Cocoa Powder (63g)
#5 Baking Powder (1/2 tsp or 3g)
#6 Salt (just a pinch!)
#7 Diet Coke (300 – 360g)
  • Any other carbonated drink will work fine (Cream Soda, Pepsi, Ginger Ale, Sparkling Water…)
  • 310ml was the sweet spot for me
  • Milk/ Coffee / Water with extra baking powder has been said to work if you can’t access carbonated beverages 😊

but Heather… where are your pictures?

I was hesitant to share these pictures because I forgot to take the tinfoil covering off when the brownies were cooling… resulting in a moister and flatter brownie than what would’ve been otherwise. Aka uglier photos (but still decadent nonetheless!).

However, to prove that I did indeed try this recipe out, here’s a photo. You might recognize it from the Pinterest graphic below hehe.

Heather's take on Boo's Ridiculous(ly low calorie) Brownie with a shiny, crinkled crust created using erythritol as a sweetener in place of sugar. Bird's eye shot on parchment paper on a wooden stool as backdrop :)

Pin this before you forget!

*Full macros and nutrient info beneath directions!*

Okay, now on with the recipe!

Yield: 16

Boo's Ridiculous Brownies

Boo's Ridiculous Brownies

The recipe yields 16 2" square brownies baked in an 8x8 inch pan. All quantities displayed below are triple those of Boo’s original single-serve recipe, and slightly adjusted to my preferences and what I had on hand: Instead of whey protein, I used PEScience’s Whey-Casein blend. I also used oat flour in place of all purpose flour and reduced Erythritol from 135g to 100g. 

Prep Time 5 minutes
Cook Time 30 minutes
Total Time 35 minutes


  • 63g Cocoa Powder
  • 36g Select Protein in Frosted Chocolate Cupcake by PEScience
  • 45g Oats, ground into flour
  • 100g Erythritol
  • 3g (1/2 tsp) Baking Powder
  • Pinch of salt
  • 300g carbonated beverage of choice


  1. Preheat your oven to 190°C (375°F)
  2. In a large bowl, combine dry ingredients (cocoa, protein powder, oat flour, erythritol, baking powder and salt.. everything but your carbonated liquid) until evenly distributed. My cocoa powder was clumpy, so I used a sieve to break up all the lumps! 
  3. Into the dry mixture, lightly stir in your carbonated beverage until no lumps remain. The batter should be very liquid and begin spewing bubbles! Immediately pour into your greased/lined 8”x8” pan and bake for 25 - 35 minutes, or until a toothpick comes out clean when inserted. 
  4. Let cool in the pan for 5 more minutes after baking, then an additional 30 minutes out of the pan before slicing and storing. As Boo notes, the brownies continue to cook in the pan after leaving the oven, and may not have set completely. 
  5. Bonus tip: I wrapped mine individually in aluminium foil (because portion control lol) and reheated them in the microwave with a dollop of peanut butter… SO FUDGY! 


  • 63g Cocoa, Dry Powder, Unsweetened, Processed With Alkali: 140 kcal
  • 36g PEScience: 120 kcal
  • 45g Oats, Regular And Quick And Instant, Unenriched, Dry: 171 kcal 
  • 100g Erythritol Pure, Non-GMO NOW: 24 kcal
  • 3g Leavening Agents, Baking Powder, Low-sodium: 3 kcal
  • 1 pinch Salt: 0 kcal
  • 290-310g Diet Coke Coke: 0 kcal

Total: 457 kcal

Per 1 of 16 pieces: 28.56 kcal

Nutrition Information



Serving Size

2" square brownie

Amount Per ServingCalories 28.5Total Fat 0.8gSaturated Fat 0.4gTrans Fat 0gCholesterol 1mgSodium 18mgCarbohydrates 4.2gFiber 1.5gSugar 0.1gProtein 2.7g

Let me know how you like it!

16 thoughts on “Boo’s Ridiculous Brownies (29 calories & anabolic)”

    1. So glad to hear that you love them as much as I do, Micah! Coconut yogurt and almond butter for toppings sound divine!

  1. Hi! Would any chocolate protein powder work? I can’t have artificial sweeteners and sadly the one in the recipe has sucralose. I really want to try these!

    1. Hey Amy, while a whey-casein blend is most ideal, any chocolate protein powder should do the job. Do let me know how it turns out!

  2. These are pretty good, but I wouldn’t use coke again as you can really taste it…
    Very squidgy texture! Not amazing on their own but really good with icecream or custard!

Leave a Reply

Your email address will not be published. Required fields are marked *